Most vehicles, such as off-highway trucks, include suspension systems with a plurality of gas-over-liquid struts that operate to dampen the oscillatory motion caused by the vehicle's engagement with the ground. For instance, many off-highway dump trucks, include a suspension system with four struts positioned to support the payload of the truck. In off-highway trucks, the struts not only help smooth the ride, the struts also can aid in estimating a payload carried by the truck based on a known relationship between strut pressure and payload. The estimated payload can be used to estimate truck productivity, which in return, can help a business better plan for the future.
However, struts are not always in good working condition, and are subject to faults, such as being undercharged, often referred to as collapsed, or being overcharged. Operation of the vehicle with a faulty strut can cause uneven tire wear that can lead to unscheduled maintenance or tire failure. Moreover, a completely collapsed strut can lead to extensive structural damage due to repeated metal-to-metal contact. In addition, a faulty strut can adversely affect the accuracy of a payload weight estimation, which can lead to detrimental business decisions.
Over the years, there have been methods developed for detecting a faulty strut. For instance, a faulty strut can be detected through operator inspection. However, operator inspection is subject to human error and often cannot detect a fault that occurs during operation until after the operation has ended. There have been methods developed for indicating a faulty strut during operation of the truck. These methods generally compare the relative motion of at least two struts on the truck for a predetermined period of time, and thus, operate under the assumption that the load of the truck is equally distributed. For instance, a method for detecting a collapsed strut in a moving truck, set forth in U.S. Pat. No. 4,887,454, issued to Kyrtsos et al., on Dec. 19, 1989, requires a step of comparing strut pressure among the plurality of the truck's struts. Thus, the Kyrtsos method of detecting a collapsed strut requires a vehicle with more than one strut, and can be relatively complicated and time consuming.
The present disclosure is directed at overcoming one or more of the problems set forth above.